6- Nitrosalicylic acid

Nitrosalicylic acid [96-97-9] M 183.1, m 233 , pK 2.32, pK 10.34. Crystd from acetone (charcoal), then twice more from acetone alone. 

Nitrosalicylic acid, 22 5 Nitrosamine formation, ascorbic acid and,... 

The stepwise stability constants for V complexes with glutamic, aspartic, W -ethylenediaminedisuccinic, and W -ethylenediamine-bis-(a-glutaric acid) have been reported.The 1 1 oxovanadium(iv) complex of 5-nitrosalicylic acid has been characterized = 710 nm), and the mixed species formed between vanadium(iv) with protocatechuic acid (H3L ) or gallic acid (H L ) and 4-aminoantipyrine (aant) have been identified spectroscopically as the 1 1 1 and 1 2 2 HL (HL ) aant complexes. The species present in solutions of and tartaric acid below pH 2 have been identified as [VO-... 

Reaction with cold nitric acid results primarily in the formation of 5-nitrosalicylic acid [96-97-9]. However, reaction with fuming nitric acid results in decarboxylation as well as the formation of 2,4,6-trinitrophenol [88-89-1] (picric acid). Sulfonation with chlorosulfonic acid at 160°C yields 5-sulfosalicylic acid [56507-30-3]. At higher temperatures (180°C) and with an excess of chlorosulfonic acid, 3,5-disulfosalicylic acid forms. Sulfonation with liquid sulfur trioxide in tetrachloroethylene leads to a nearly quantitative yield of 5-sulfosalicylc acid (1). 

Prepd by esterification of 5-nitrosalicylic acid with ale H2SO4... 

Chromium tetraphenyl acid 5-nitrosalicylate, (C6H5)4Cr.02C. C6H3(0H)(N02) C02H.CeH3(0H)(N02), is isolated from the pentaphenyl base and two equivalents of 5-nitrosalicylic acid. It crystallises in rosettes of needles, M.pt. 132° C. 

Nitrosa1icylic acid, AJ21 L-Nitrosalicylic acid, AJ22 5-Nitrosalicylic acid, AJ23... 

Nitrosalicylic acid potassium salt Hydrazine hydrate... 

Procedure A To 5-nitrosalicylic acid potassium salt (55 g, 246 mmol) dissolved in water (200 mL) was added potassium hydroxide pellets to reach pH 11.5. To this solution 2 g of Raney nickel were added. The mixture was heated-up to reflux and hydrazine hydrate (40 mL, 80% in water, 64 mmol) was added dropwise during 3-4 hrs. The reflux was maintened until HPLC showed the disappearance of the starting material and the complete reduction of 5-nitrosalicylic acid (3-4 hrs). The hot mixture was filtered under nitrogen and the solution was collected. The solution was cooled to 40°C and the pH was adjusted to 2.3 by addition of 35% HCI aqueous solution. The precipitation of 5-aminosalicylic acid occurred. The solution was cooled at 0°C, and after standing at this temperature for 2 hr, the precipitate was filtered, washed with water, and dried at 60-70°C. 5-Aminosalicylic acid was obtained in 89% yield. 

Dilute nitric acid When a salicylate or the free acid is boiled with dilute nitric acid (2m) and the mixture poured into 4 times its volume of cold water, a crystalline precipitate of 5-nitrosalicylic acid is obtained. The precipitate is filtered off and recrystallized from boiling water the acid, after drying, has a melting point of 226°. 

Diacetoxymercuri-5-nitrosalicylic acid is obtained by heating 5-nitrosaIicy)ie acid witis 2 mols, of mercuric oxide in hot glacial acetic acid, filtering whilst hot and cooling, wlien white ciy stals are deposited. These arc reerystallised from acetic acid and become pale yellow when dry. 

Filler et a/. attempted to cleave the methyl ether (2) with strong acids or bases but found that the CF3 group is also attacked, with formation of 5-nitrosalicylic acid (1). Cleavage to the desired phenol (3) without disturbance of the trifluoro-... 

Dinitroorthocresol (DNOC, 36), the metabolism of which has been studied most extensively, is excreted in the urine of rabbits at a rate of about 20% in 48 hours, of which 5-6% is voided in the form of the free compound, about 1 % as O-conjugate (37) and 12% mainly as 2-acetamino-6-methyl-4-nitrophenol O-conjugate (38). The metabolites 3-amino-5-nitrosalicylic acid and 4-amino-6-methyl-2-nitro-phenol have been observed in trace quantities. The amino groups formed by... 

A solution containing salicylic acid and an excess of aluminum nitrate develops an intense blue color when heated to about 100°C for 4-5 minutes. The aluminum chelates formed, when cleaved with HC1, give a 56% yield of phenolindophenol-3,3 -dicarboxylic acid and 5-hydroxysalicylic acid and 5-nitrosalicylic acid in 12% and 10% yields, respectively. Reaction scheme (XV) has been advanced to explain the products formed. 

As a result of the partial oxidation of 5-nitrososalicylic acid, 5-nitrosalicylic acid is formed. The nitrates of chromium, zirconium, thorium, and gallium could be used in place of aluminum nitrate to give the same reac-... 

Figure 99. Effect of humidity on the degradation of acetyl-5-nitrosalicylic acid (A) and glutathione (O) at 80°C. (Reproduced from Ref. 431 with permission.)...

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